Sunspots as proxy for TSI

[Pmt111500]

I couldn't find a sunspot thread either. I used sunspots as a proxy when trying to isolate the ENSO effect vs global temperature once upon a time, so this might be of some interest.

It maybe relevant to note in the start that Arctic is a dark place in winters. Solar wind though produces some auroras during sunspot maxima, they happen high in atmosphere on gases that are generally inert wrt infrared radiation that global warming is about. If I remember correctly, there was some sort of revision not too long ago (2014? Or was it even 2016?) concerning the sunspot counts in early records, so it might be advisable to dismiss articles prior this as being outdated. Google search by topic headline below, attached a couple of quite recent open source pdfs that were quite on top of the search.

https://www.google.fi/search?q=sunspots+as+proxy+for+tsi&oq=sunspots+as+proxy+for+tsi&aqs=chrome..69i57j33.20271j1j4&client=ms-unknown&sourceid=chrome-mobile&ie=UTF-8#ip=1

[oren]

Thank you Pmt. I have this idiotic mental barrier, a newbie symptom, in that I have never started a thread on ASIF, in the belief that all subjects have probably been discussed before my time, and that my peers here know better than me anyway. I have seen enough unnecessary threads to know that this is a task best done after careful consideration. So I am happy you dealt with the issue...

[SteveMDFP]

Thanks for creating the thread.  I'll remove my contribution below from that wrong thread:

The sun's energy is measured by TSI, not sunspots, if my limited understanding is correct.
I do wish for a different thread to discuss this, if anyone can find such.

oren Total Solar Insolation is a combination of the output of the sun and the ability of the environment to retain it.  It includes output, reflection, absorption and the season/angle of impact.  Clearly if the output is less, then the environment has to be different to keep more of it.

No, not quite right.  Ability of the environment to retain solar irradiation is not part of TSI.  "Total Solar Irradiance (TSI) is a measure of the solar power over all wavelengths per unit area incident on the Earth's upper atmosphere. It is measured perpendicular to the incoming sunlight."  It's measured from space, not the surface of the earth.

[oren]

And now on topic. I have been seeing claims that "solar TSI has been sub-normal for 12(+?) years (including 3+ years of TSI setting a 100 year record low)".
I know nothing of the subject at hand, but a quick google search found a chart for sunspots, and a chart for Total Solar Irradiance or TSI, and they seem to correlate but nor equate.

Definition from Wikipedia: Steve already beat me to it...

A measurement of TSI by the SORCE mission, starting in mid-2003.


A historical reconstruction of TSI.


Both charts don't seem to support the claim quoted above. The 2015 peak has been above the 2004 peak in the first chart, and the overall TSI seems to be higher than it was 100 years ago. But maybe I misunderstood the specific claim.

A historical sunspot activity chart.


So the way I see it, sunspot activity has been very low during the last cycle, but TSI has not been very low compared to the previous cycle.
Now maybe this properly belongs in the stupid questions thread, but - what am I missing?

[SteveMDFP]

I would just like to point out that the total range of TSI here is from 1360 to 1362.  Two parts in 1300.  It's inconceivable to me that solar variation has any measurable impact on climate, in comparison to far more potent effects like CO2, particulates, land use changes, etc.

Back in pre-industrial times, these minute changes in solar output could possibly trigger various feedbacks that could result in measurable changes.  In the modern era, I just don't think the idea holds any water at all.

[kassy]

Sunspots are an ok but imperfect proxy:
https://tamino.wordpress.com/2016/04/22/sunspots-and-solar-output/

The sunspots are the dark spots we counted. They are darker areas.
TSI includes the bright spots too:

Recent satellite observations have found that the Total Solar Irradiance (TSI), the amount of solar radiation received at the top of the Earth's atmosphere, does vary -- see the graph for the results from six satellites. "The variations on solar rotational and active region time scales are clearly seen. The large, short-term decreases are caused by the TSI blocking effect of sunspots in magnetically active regions as they rotate through our view from Earth. The peaks of TSI preceding and following these sunpot "dips" are caused by the faculae of solar active regions whose larger areal extent causes them to be seen first as the region rotates onto our side of the sun and last as they rotate over the opposite solar limb." [Excerpted from the UARS descriptive text] The TSI provides the energy that determines the Earth's climate.

https://www.ngdc.noaa.gov/stp/solar/solarirrad.html

[wili]

Steve wrote:

I would just like to point out that the total range of TSI here is from 1360 to 1362.  Two parts in 1300.  It's inconceivable to me that solar variation has any measurable impact on climate, in comparison to far more potent effects like CO2, particulates, land use changes, etc.

Back in pre-industrial times, these minute changes in solar output could possibly trigger various feedbacks that could result in measurable changes.  In the modern era, I just don't think the idea holds any water at all.

As I recall, variations in insolation are at most only about a tenth of the effect of warming from all AGW sources (as the graph that ASLR posted on the other thread shows nicely!). So yeah, relatively insignificant, but not nothing.

[SteveMDFP]

Sunspots are an ok but imperfect proxy:
https://tamino.wordpress.com/2016/04/22/sunspots-and-solar-output/

The sunspots are the dark spots we counted. They are darker areas.
TSI includes the bright spots too:

Recent satellite observations have found that the Total Solar Irradiance (TSI), the amount of solar radiation received at the top of the Earth's atmosphere, does vary -- see the graph for the results from six satellites. "The variations on solar rotational and active region time scales are clearly seen. The large, short-term decreases are caused by the TSI blocking effect of sunspots in magnetically active regions as they rotate through our view from Earth. The peaks of TSI preceding and following these sunpot "dips" are caused by the faculae of solar active regions whose larger areal extent causes them to be seen first as the region rotates onto our side of the sun and last as they rotate over the opposite solar limb." [Excerpted from the UARS descriptive text] The TSI provides the energy that determines the Earth's climate.

https://www.ngdc.noaa.gov/stp/solar/solarirrad.html

Well, yes, sunspot number is a fairly good proxy for TSI.  But for years where TSI is available, there's no point I can see to considering sunspots.
While sunspot numbers vary dramatically over a cycle, the TSI variation is tiny, about 2 parts in 1300. 
I'd suggested that modern changes in various forcings utterly overwhelm such tiny variations in TSI.  I'm attaching a graph from SkepticalScience, which shows only a vague relationship between TSI and climate up to about 1970, and then an utter divergence.  This would be at least consistent with my point here.

[kassy]

TSI is indeed superior (and it's variation is irrelevant for our future).

I merely meant to point out the different things sunspots and TSI measure.

[jacksmith4tx]

The most interesting thing about sunspots is as a possible precursor to a coronal mass ejection. The sun could blast the planet with a civilization crippling dose of radiation and plasma with little warning. We missed one that was about as strong or stronger than the 1859 Carrington event just a few years ago.
The Solar Superstorm of July 2012
https://science.nasa.gov/science-news/science-at-nasa/2014/23jul_superstorm

[mostly_lurking]

I would just like to point out that the total range of TSI here is from 1360 to 1362.  Two parts in 1300.  It's inconceivable to me that solar variation has any measurable impact on climate, in comparison to far more potent effects like CO2, particulates, land use changes, etc.

2/1300 > 100/1000000  (rise in co2 levels)

[crandles]

2/1300 > 100/1000000  (rise in co2 levels)

Yes but 2/1300 variation is a fairly regular cycle which evens out to a long term trend of practically nothing, whereas the CO2 keeps going on up and up. So not a fair comparison - variation in cycle vs trend. To do it properly it should be trend vs trend.

[Ned W]

I would just like to point out that the total range of TSI here is from 1360 to 1362.  Two parts in 1300.  It's inconceivable to me that solar variation has any measurable impact on climate, in comparison to far more potent effects like CO2, particulates, land use changes, etc.

It's not really the ratio that matters here, it's the number of watts per square meter. 

Start with that range of 2 W/m2 (but note that most of the time it varies within a much narrower range).

Divide by 4, because the circular cross-section of the solar beam is being projected over the spherical surface of the Earth.  (The surface area of a sphere is 4x the area of a circle with the same radius).

Then multiply by 0.7, to account for the Earth's albedo (30% of incoming shortwave radiation is reflected).

That works out to a total range of variation of 0.35 W/m2 for the absorbed fraction of TSI, over all of the historical record.  And as crandles points out, it's not a linear trend, more of an irregular oscillation. 

Meanwhile, the forcing from CO2 over the same time period is nearly 10X larger.  And it's not an oscillation, it's a (nonlinearly increasing) trend.

[SteveMDFP]

That works out to a total range of variation of 0.35 W/m2 for the absorbed fraction of TSI, over all of the historical record.  And as crandles points out, it's not a linear trend, more of an irregular oscillation. 

Meanwhile, the forcing from CO2 over the same time period is nearly 10X larger.  And it's not an oscillation, it's a (nonlinearly increasing) trend.

My understanding continues to be refined here.  Thanks.

[Ned W]

You're welcome.

We all run up against this "It's the Sun!" claim.  Usually along the lines of "There's gonna be another Maunder Minimum and we'll all freeze."

Well, if someone is acting alarmed by the natural variation in solar irradiance, they should be utterly terrified by the 10X larger (and growing!) trend in warming from CO2.

[Pmt111500]

Appropriate would be to compare to the rise since preindustrial, as Maunder minimum was back then. The CO₂ amount in atmosphere has risen ~40% since. Since some are friends of alt-facts, I'll drop an alt-quote here:
"It's not easy to change the temperature of a planet, but with modern technology it is possible", Svante Arrhenius, Rock Bar Stockholm, 1902. (Pmt, location correct, ~1994)

[Sleepy]

Some more stuff that might be interesting (along with my stupid comments) from this thread:
https://forum.arctic-sea-ice.net/index.php/topic,2250.msg141798.html#msg141798

http://solar-center.stanford.edu/sun-on-earth/Solar%20Influences%20on%20Climate-2009RG000282.pdf

A value of 0.24 W m−2 solar radiative forcing difference from Maunder Minimum to the present is currently considered to be more appropriate.

https://www.swsc-journal.org/articles/swsc/pdf/2017/01/swsc170014.pdf

Abstract – The Maunderminimum (MM) was a period of extremely low solar activity from approximately AD 1650 to 1715. In the solar physics literature, the MM is sometimes associated with a period of cooler global temperatures, referred to as the Little Ice Age (LIA), and thus taken as compelling evidence of a large, direct solar influence on climate. In this study, we bring together existing simulation and observational studies, particularly the most recent solar activity and paleoclimate reconstructions, to examine this relation. Using northern hemisphere surface air temperature reconstructions, the LIA can be most readily defined as an approximately 480year period spanning AD 1440–1920, although not all of this period was notably cold. While the MM occurred within the much longer LIA period, the timing of the features are not suggestive of causation and should not, in isolation, be used as evidence of significant solar forcing of climate. Climate model simulations suggest multiple factors, particularly volcanic activity, were crucial for causing the cooler temperatures in the northern hemisphere during the LIA. A reduction in total solar irradiance likely contributed to the LIA at a level comparable to changing land use.

[Neven]

Posted in the wrong thread by mostly_lurking:

As to the TSI: If the tiny decline in TSI were significant sea ice volume and extent would have been increasing for the past twenty years. That is not the case.

FOW, I did post the link to the RealClimate article which addressed this.  Even if the sun dropped into a Maunder Minimum, GHG emissions would overcome it in a few decades.

The emissions have already overwhelmed this signature.  All it does is retard the decline very slightly, if much at all.  The noise in the system is much higher than a small decline in TSI.

I'm going to do a no-no for this forum and link a video from what you would call a skeptic of sorts. It does have relevance to the TSI subject. It's only 6 minutes and if you can forget the source for a second- I would like to know what you think.  Is it hogwash or has any merit?
I'll understand if I'm banned for this

[Neven]

I've watched the Suspicous0bserver stuff, so I'll just post some Pothole stuff to counteract (please, don't post any more videos of the kind):

[Ned W]

Posted in the wrong thread by mostly_lurking:

As to the TSI: If the tiny decline in TSI were significant sea ice volume and extent would have been increasing for the past twenty years. That is not the case.

FOW, I did post the link to the RealClimate article which addressed this.  Even if the sun dropped into a Maunder Minimum, GHG emissions would overcome it in a few decades.

The emissions have already overwhelmed this signature.  All it does is retard the decline very slightly, if much at all.  The noise in the system is much higher than a small decline in TSI.

I'm going to do a no-no for this forum and link a video from what you would call a skeptic of sorts. It does have relevance to the TSI subject. It's only 6 minutes and if you can forget the source for a second- I would like to know what you think.  Is it hogwash or has any merit?
I'll understand if I'm banned for this

Ugh.  I think you'd need someone with a higher level of expertise in solar physics to debunk that.   Maybe Mike Lockwood, or someone like that? 

It sounds to me like a lot of garbage dressed up in pseudo-scientific terminology, but it's not my area.  The main thing is that it's all ... talk.  They never sit down and walk you carefully through a process of quantifying the impact of their claims on the global temperature record.  It's all about creating an impression of a problem without actually quantifying it.



Plus, any actual facts in there are wrapped up in a nauseating package of sneering attacks on climate science.  The voice + words were annoying enough that if anyone other than you, Neven, had asked me to look at it, I would have turned it off before the halfway point. 

[wili]

You don't have to be a solar scientist to see why the 'climate coupling' film is full of crap.

I also couldn't stand the sneering tone, but I only needed to make it through the first minute and a half or so to see where he was going.

It's just the same old tired claim that 'it's the sun.' That it is fluctuations in the sun's strength that completely control the earth's climate. There are many reasons that this is obviously total bs.

I'll just point out for now that all the patterns of warming point to GHG, not changes in insolation, as the culprit:

night warming is greater than day warming even though the sun shines most in the day;

polar warming is greater than tropical warming, even though the sun shines most in the tropics;

troposphere warming more than stratosphere warming, even though the stratosphere is closer to the sun...

There are others such patterns along this line of reasoning that I'll let other elucidate. And that's not to mention that solar activity has been steady to slightly declining over the past few decades, even as gw has started to go into over drive. And all other planets aren't heating up, even though they are all exposed to the same sun...and on and on and on...

I thought that this was one place where we wouldn't have to see the endless repetition of the same old de-bunked and rererererererere...debunked idiocy floated about ad nauseum.

Was there some point to this little exercise that some how eluded me?

[Ned W]

You don't have to be a solar scientist to see why the 'climate coupling' film is full of crap.

I was saying that it would take someone in the field to rebut the specific details, not just dismiss the general concept.  But I agree with your heaping scorn on the general concept. 

Was there some point to this little exercise that some how eluded me?

Whatever it was, it eluded me, too.

[Rodius]

The reason for this being brought up may elude you, but for me it is helpful as this information is now in one place.

Not being in the sciences myself, when refuting claims like this, I need to be able to refer back to the information for a while before I no longer need to refer back to it.

So, if the reason eludes you, I am glad it is here as it helps me learn more and to steer people away from the "Its the sun" argument.

[wili]

Rodius, glad you found something useful in our responses.

If you need a one-stop-shop for debunking denialist dummies, try:

https://www.skepticalscience.com/argument.php

Note that 'It's the sun' is number 2, indicating just how worn out and over used that particular lie is.

Also see: https://www.skepticalscience.com/10-Indicators-of-a-Human-Fingerprint-on-Climate-Change.html

Also, besides the fact that the poles, the night and the troposphere are warming faster than they would if warming was due only to (non-existent) increased solar activity, winters are also warming at a faster rate than summers are--again, the exact opposite of what would happen if the sun were responsible for the increase in global warming.

[NeilT]

I introduce sunspots, solar cycle and TSI for one reason and one reason only.  Whilst the solar variance during the oscillation from max to min has nothing whatsoever to do with the climate and whilst the difference between solar cycles also has very little to do with the changes we see in the climate (in fact the slight dimming of the sun should be making it very slightly cooler).

I do, however, believe that the oscillation between min and max does have a very slightly measurable impact on the Arctic melt seasons.  More of a contributing factor than a main driver.

As the ice disintegrates, I think that smaller contributing factors will play a more visible role in how the melt seasons play out.  More melt at the peaks, more retention at the troughs.

It is just a theory and no way to really prove it and will probably take another 15 years of observations to even check out whether it is real or not.

It is just something to watch.  The last minimum was 2008/9.  It looks like this one is going to be 2018/19.

It is looking like this melt season will finish somewhere between 5th and 7th in the record.  Given the dramatic start to the season, that is, of itself, quite interesting.

Should 2019 exhibit similar trends, then it will be just one more datum point in the record.  After around 25 years of watching, I'm not really that impatient to know.

[Human Habitat Index]

For people who struggle to understand climate science, I ask them, what planet is closer to the sun,
Mercury or Venus. Then I ask them which is hotter.

[morganism]

oops, just posted under the orbital irradiance video above

Solar total and spectral irradiance reconstruction over the last 9000 years

https://arxiv.org/abs/1811.03464

"The concentrations of the cosmogenic isotopes 14C and 10Be in natural archives have been converted to decadally averaged sunspot numbers through a chain of physics-based models."

"Over the last 9000 years, the reconstructed secular variability in TSI is of the order of 0.11%, or 1.5 W/m2."

[Sleepy]

Thanks, adding Fig7 from the above.